Describe the intervals over which the given function is decreasing

Tell whatever the ordered pair is a solution of the given system.

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

What is the solution to the division problem below x3+x2-11x+4/x+4